Products in the form of cough syrups and candy-based cough drops have long been known as vehicles for the delivery of medicaments aimed at soothing sore or irritated throats. Such medicaments include analgesics, antitussives, expectorants, cooling agents such as menthol, and warming agents such as ethanol or gingerol. The material can be administered swallowing a liquid cough mixture or by way of a throat drop or lozenge which releases the active agent upon sucking. Particularly in the case of a volatile active agent, the product can also provide relief from cold symptoms by way of clearing the nasal passages.
EP-A-431,376 describes hard confections for sustained release treatment of sore throats comprising hydrogenated isomaltulose and an active ingredient which can be an antitussive or antihistamine but can also be a volatile oil such as menthol or eucalyptus. The confection normally contains a further flavouring agent such as lemon, honey or cherry but which can also be menthol or eucalyptus.
The art has also described methods of enhancing the effects of volatile oils in cough drops and the like. Thus U.S. Pat. No. 4,762,719, to Forester, published Aug. 9, 1988, describes a cough drop with a hard candy outer shell and a powdered centrefill. The centrefill composition comprises an active ingredient, such as menthol and eucalyptus, and a rapidly dissolving powder, such as sorbitol, xylitol or dextrose monohydrate, which desirably has a negative heat of solution to accentuate the cooling effect of the actives. The shell may further comprise a flavour such as cherry, lemon, orange, lime, etc.
U.S. Pat. No. 4,980,169, to Oppenheimer et al., assigned to the Warner-Lambert Company, published Dec. 25, 1990, describes cough drops in which the flavour is enhanced by incorporation a sensorially undetectable amount of a volatile oil modifying agent, especially capsicum.
It has now been found that the perceived effect of a physiological warming or cooling agent can be enhanced by incorporating a warming or cooling agent into a first composition which is administered along with a second composition which provides for delayed release of a cooling or warming agent. The first and second compositions are suitably provided by a centre-filling confectionery composition in which the shell provides the first composition and the filling provides the second.
It is accordingly an object of this invention to provide medicated confectionery compositions, especially throat drops, delivering enhanced throat and nasal warming or cooling.